1. Field of the Invention
The present invention relates to microarrayer apparatus, and in particular to a manually operable spotting station.
2. Discussion of the Prior Art
At the simplest level, a microarrayer is a system for transferring material from one location, the source, to a second location, the target. In practice, source material is usually biological material contained in a microtitre plate, and the target is either a glass microscope slide or nylon filter.
Microarrayers are used to spot DNA or other biological material onto glass slides or other rigid substrates. It is possible to produce microarrays using either an automated system or by hand.
Robotic systems have several advantages: they are fast and accurate and produce large numbers of identical arrays. They are, however, also relatively expensive from the point of view of initial purchase costs.
It is feasible to produce an array by hand if only a few slides, each with 200 different samples or less, are required. However, hand-spotting an array is only really practical with a feature pitch of approximately 1.0 mm (the feature pitch is the centre to centre distance between adjacent spots). Using a pitch of 1.0 mm and an 8.times.12 grid layout, which corresponds to a standard 96 well microtitre plate, allows up to 6 grids to be fitted on to a standard microscope slide. However, this does not leave much of a handling margin. Therefore, conventionally only two grids per slide are usually provided. Each grid can be different, or they can be duplicates. Because the most time-consuming element of producing an array is the cleaning cycle, it is common to work on several slides at the same time.
It is desired to provide apparatus to assist in producing microarrays which is substantially cheaper than fully automated systems and which enables an operator to produce a microarray more quickly, accurately and at a smaller pitch spacing than is conventionally possible using the naked eye.